This ruling by Switzerland’s highest court overturned a lighter sentence previously given by an administrative court, deciding in favour of clear punishment in the case of unsafe tyres on vehicles.

At the hearing on Aug. 7, the court was told about a professional driver who had been stopped in May last year during the course of a police check in wet weather. The tread depth on the vehicle’s tyres was in part below the minimum specified limit of 1.6mm. According to the federal judges, this was something the driver would have been able to see and he should have replaced the tyres. Continuing to drive with tyres this worn was considered to be a moderately serious offence, as it posed a danger to others.

As tyremaker Continental point out, in the rain tyres with insufficient tread depth are unable to adequately disperse the water from the ground contact patch and therefore tend to aquaplane as well as to require longer braking distances in the wet. Tyre experts at Conti, therefore, recommend  switching to new tyres as soon as the tread depth goes down to three millimetres.

In the U.K. tyres are legally required to have a minimum 1.6mm tread depth in a continuous band throughout the centre three-quarters of the tread width. And while U.K. law in relation to tyres currently does not have the bite of its Swiss counterpart, motorists at the wheel of vehicles wearing tyres below this minimum level run the risk of losing up to 3 penalty points and a fine of £2,500 per tyre if caught with tyres worn below the legal minimum.